Background: Considerable discussion continues about effective ways to achieve desirable healthcare outcomes. An electronic health information system has been the focus of many discussions, especially at the Addiction Research and Treatment Corporation (ARTC). ARTC is an outpatient opioid treatment program providing primary medical care and HIV-related care for approximately 3,000 predominantly minority adults in Brooklyn and Manhattan in New York City. This economically disenfranchised population is also infected with hepatitis C virus. These patients are subject to significant disparities in healthcare access and quality compared to the general population. At ARTC, little information, especially clinical data, is stored electronically. There are few electronic systems; these are not integrated with each other. To test various hypotheses, ARTC will assess, over a three-year study, the implementation of an electronic health information system integrating counseling and social services, medical services, case management, HIV counseling and testing, dispensing information, administrative and fiscal data. Methods: Four specific aims (quality, productivity, satisfaction, and risk management) and one secondary aim (financial performance) will be examined to assess the impact of an electronic information system; these were selected from pre-study needs assessments involving stakeholders (patients, clinicians and managers) and/or prior published investigations. A number of hypotheses are proposed within each specific aim. For each quantitative measurement selected, the data sources will be either surveys of stakeholders or will be derived directly from the information system. Measurements will be assessed pre and post-implementation of an integrated electronic health information system for statistically significant changes. Conclusion: The results may have the potential to inform continuing discussions about the impact of integrated electronic systems in enhancing agency cost-effectiveness in substance abuse treatment settings. Because the patient population is largely economically disenfranchised and suffers disproportionately from HIV and HCV infection, the study findings have the potential to be responsive to the challenges of these infections and the healthcare disparities suffered by this patient population. [unreadable] [unreadable] [unreadable]